Abstract

For highly charged ions with 3 to 10 electrons, we derive explicit, closed-form quantum states which become exact in the high charge limit. When combined with suitably renormalized experimental data across isoelectronic sequences, these quantum states provide a widely applicable route to predicting electronic configurations and term values for neutral atom energy levels. Moreover, our findings allow the prediction of missing levels, suggest that certain current term assignments for five-electron ions are incorrect, and provide insight into the rare failure of Hund's rules in excited states.